The invention is based on an internal combustion engine having an intake module or intake tube fastened to the engine, and a method for fastening an intake module to an engine as generically defined hereinafter.
Internal combustion engines to which air or a fuel-air mixture is supplied via an intake tube exist. A fastening means holds the intake tube or intake module against the engine in a retention direction. In the known embodiments, the fastening means includes a plurality of fastening screws, with which the intake tube is held against the engine, and especially against a cylinder head of the engine. For mounting the intake module or intake tube on the engine or for dismantling it from the engine, the heads of the fastening screws must be accessible to a suitable turning tool. The cylinder head closes off a crankcase or cylinder tube of the engine from the top and receives gas exchange devices, for instance. Moreover, together with a piston of the engine, it forms a desired combustion chamber shape. In internal combustion engines typical for passenger cars, usually one cylinder head is used for all the cylinders of the engine.
In modern internal combustion engines, an increasing number of additional components are connected to the intake tube. The components include for instance a throttle device, a control unit, a pressure sensor, a temperature sensor, an injection valve, a fuel distributor element, an ignition coil, a tank venting valve, and other final control elements, sensors, cables, hoses and so forth. There may even be multiple examples of these components provided on one intake tube. The intake tube, together with the components mounted on it or integrated with it is often referred to as an intake module. Since a not-inconsiderable number of different components is mounted on the intake tube of the intake module, the intake module is often relatively bulky, which makes for poorer accessibility to the fastening screws. It is often necessary for the intake tube to be firmly screwed to the cylinder head of the engine first by the fastening screws, before the other components can be fastened to the intake tube. As a result, it is not possible to keep the intake module on hand, complete with all its components assembled, for fastening to the engine. Testing of the complete intake module before it is mounted on the engine is also almost impossible.
Since the fastening screws are often not accessible once the intake module has been fully assembled, removal of the intake tube from the engine first requires that at least some of the components of the intake module must first be removed from the intake tube, before the fastening screws that hold the intake tube on the engine become accessible.
Often the intake tube itself is also already quite bulky and complicated in shape. Therefore even if only the intake tube, without additional components, is to be fastened to the engine, access to the fastening screws is often considerably more difficult, and the engineer is quite limited in terms of designing the intake tube.